No idea - this is my firefox sync NixOS config, in its entirety:
age.secrets.ffsync.rekeyFile = secrets.ffsync;
services.firefox-syncserver = {
enable = true;
secrets = config.age.secrets.ffsync.path;
settings.hostname = "localhost";
singleNode = {
enable = true;
hostname = "0.0.0.0";
capacity = 2;
};
};
Probably... I mean, I'd at least start it in a systemd service, but sure, you don't need a domain.
But of course your mobile won't be able to access that domain outside your network